Tactical dinghy compass

ABSTRACT

A compass having a color coded compass card for enhanced reading of the compass. The compass card is divided into four quadrants each of which is further subdivided into equal sectors differently colored within each quadrant; the color sequence of the sectors within each quadrant is repeated in each quadrant. The color sequencing enables an efficient method of navigating a sailing dinghy around an olympic course.

TECHNICAL FIELD

This invention relates to an easy to read compass and a method ofnavigating a sailing dinghy.

BACKGROUND ART

The crew of a sailing dinghy normally have considerable difficulty inreading a tactical compass while sailing. This is because the compass isgenerally mounted centrally within the dinghy yet the crew are on theside of the dinghy and leaning outwardly, or may be suspended by atrapeze, to balance the dinghy and prevent it from capsizing. Underthese circumstances a traditional compass marked with numbers or lettersor both is extremely difficult, if not impossible, to read.

The crew of a sailing dinghy often must be preoccupied with positioningthemselves so as to keep the dinghy upright so that a centrally mountedcompass is simply visibly inaccessible. Even if the compass is mountedon the gunwhales of the dinghy, an outwardly leaning crew may not beable to read the numbers or letters on a compass card. These problemsare particularly acute in single handed sailing craft such as Laserclass dinghys or sail boards where the single crew has both his handsoccupied in controlling the sheets and tiller and is often required toposition himself well away from a compass.

Further, certain calculations require to be made during a sailing race,using a traditional compass. For example, determining the favoured endof the starting line, detecting wind shifts and calculating headings tothe marks all require that the crew exercise mental arithmetic skills.The physical demands of dinghy sailing are such that it is extremelydifficult to exercise the arithmetic skills needed to make thesecalculations. Again, these problems are particularly acute for singlehanded sailors in for example Laser class dinghys or sail boards.

Compasses having marked tacking angles on adjustable peripheral bezelshave been used, however they still require the user to remember numbersand discern whether the numbers are increasing or decreasing as thecompass swings, thus allowing the user to know if he is "lifting" or"knocking" on a particular tack.

DISCLOSURE OF THE INVENTION

This invention provides a compass which allows for ease of reading in asailing dinghy and which also obviates the need for mental arithmetic inmaking the necessary calculations during a sailing race.

The invention provides a compass comprising a moveable compass card,said compass card being marked into quadrants, each quadrant beingsubdivided into a plurality of differently coloured equal sectorscomprising a colour sequence said sequence being repeated in eachquadrant.

The preferred method of reading the compass card is from above but thisdoes not exclude any arrangement whereby the compass card can be read onedge or from below.

It is also preferred that the coloured sectors are marked at 10 degreeintervals in an annulus around the circumference of the compass card.

Preferably the quadrants on the compass card are differently colouredand located separately from the coloured sectors in another annuluscloser to the centre of the compass card.

It is also preferred that a plurality of coloured lubber lines aremarked on the compass for ease of reading.

BRIEF DESCRIPTION OF DRAWINGS

By way of example only, the invention is described below with referenceto the accompanying drawings wherein:

FIG. 1 is a schematic representation of a compass according to thepresent invention; and

FIG. 2 is a schematic representation of a method of navigating anolympic course using the present invention.

MODES FOR CARRYING OUT THE INVENTION

FIG. 1 shows a compass (10) compass card (11) mounted pivotally aboutsubstantially its centre point (12) in a non-magnetic housing (13)whereon a plurality of lubber lines (14)(15)(16)(17)(18) are marked. Thecompass (10) is mounted in a sailing craft with the lubber line (14),the "keel line" substantially parallel to the centreline of the sailingcraft. The outer annulus (19) is divided into a plurality of colouredequal sectors. The colour sequence (21) within a quadrant is repeated ineach of the quadrants. The inner annulus (22) is divided into fourcoloured quadrants (23).

Between the inner annulus (22) and the outer annulus (19) a middleannulus (24) is marked with the four cardinal points and a plurality ofequally spaced bearings in degrees. The colour sequence (21) is designedto maximise the contrast between adjacent colours. Although the sequenceexampled here achieves this purpose any suitable sequence may be used.

The colours of the quadrants (23) are also chosen for maximum contrastbetween adjacent quadrants.

FIG. 2 shows a method of using the invention in navigating an olympiccourse.

The boat is firstly pointed into the wind (25) and the crew note thecolour of the sector (26) which is adjacent to the lubber line (14).

In order to determine the bias of the starting line, the boat is sailedalong the starting line (27). If the starting line is square to the windthe colour (26) will be adjacent to the lubber lines (14) and (16) or(17). If the starting line is not square to the wind direction thefavoured end is determined when the colour (26) is aft of the lubberlines (16) or (17).

When the boat is sailing into the wind it will tack throughapproximately 90°, each tack bearing approximately 45° off the mean winddirection. Therefore on a standard tack (28) the colour (26) will lieadjacent to either the lubber line (15), on a starboard tack, or lubberline (18) on a port tack.

A favourable wind shift on a tack (29) is indicated when the colour (26)moves aft of the lubber line (15) on a starboard tack, or the lubberline (18) on a port tack.

An unfavourable wind shift on a tack (29A) is indicated when the colour(26) moves forward of the lubber line (15) on a starboard tack, or thelubber line (18) on a port tack. The choice of contrasting colours inthe annulus (19) enables these wind shifts to be easily detected.

On the starboard reaching leg (30), the wing mark (32) is found bybearing away 90° from the starboard tack on a port hand around course asthe boat rounds the windward mark (31) to bring the colour (26) in thenext quadrant adjacent to lubber line (18). The choice of contrastingcolours in the annulus (22) enables the unambiguous associations ofcolour and quadrant to be quickly made by the crew.

On the port reaching leg (33) in a port hand around course, the startmark (34) is found by gybing the boat through 90° as it rounds the wingmark (32) to bring the colour (26) in the next quadrant adjacent to thelubber line (15).

Finally to set the course for the square run (35) back to the start mark(34), the colour (26) is brought adjacent to the lubber line (14).

On the downward legs to determine the "lifted" and "knocked" leg, fortacking downwind, the colour system may be used equally to advantage.

By using this method the crew can navigate an olympic sailing coursewithout carrying out any arithmetic tasks. Navigation is performedsimply by reference to a single colour relative to the appropriatelubber lines for the various legs.

I claim:
 1. A compass comprising a moveable compass card, said compasscard being marked into quadrant portions and having an annulus portion,each quadrant of the annulus being subdivided angularly into a pluralityof equal sectors each colored differently from the other sectors in thatquadrant said sectors forming a color sequence which is repeated in eachquadrant of the annulus portion.
 2. The compass as defined in claim 1wherein said quadrant portions are differently colored and located onthe said compass card separately from the said colored sectors of theannulus.
 3. The compass as defined in claim 1 wherein said sectors areat 10 degree intervals.
 4. A compass as claimed in claim 1, wherein saidannulus portion is located along the periphery of said card.
 5. Acompass as claimed in claim 1, further comprising a plurality of lubberlines marked thereon at predetermined points.
 6. A compass card for usein a compass, said compass card being circular and marked into quadrantportions and having an annulus portion, each quadrant of the annulusbeing subdivided angularly into a plurality of equal sectors eachcolored differently from the other sectors in that quadrant, saidsectors forming a color sequence which is repeated in each quadrant ofthe annulus portion.